An anti-iraq war protester's bid to unseat Tony Blair has been boosted by the defection of a senior local Labour figure and a rival candidate.

Dave Cattell, a member of Labour's Executive Committee in Mr Blair's Sedgefield constituency, was quitting the party today to support independent candidate Reg Keys.

His decision follows an announcement on Saturday by former MI5 man David Shayler to pull out of the race, to give Mr Keys a clear run at Mr Blair.

Mr Shayler appealed to other parties to withdraw their candidates in a bid to depose Mr Blair in the way anti-sleaze candidate Martin Bell did Tory Neil Hamilton in Tatton in 1997.

Mr Keys, 52, whose son Tom was one of six Redcaps murdered by an Iraqi mob, has accused Mr Blair of misleading Parliament over the reasons for the war in Iraq. Mr Cattell was resigning his Labour membership today at Mr Keys' campaign HQ.

He was to say: "I have been a member of the Labour Party for 30 years and this decision has been very hard for me. But I have become increasingly concerned by a growing number of issues associated with Tony Blair's leadership - none more so than the decision to go to war with Iraq.

"This decision has raised many questions regarding the honesty and integrity of his leadership."

Mr Keys admitted he has a "political mountain to climb" in overturning the Prime Minister's 17,713 majority.

But Mr Shayler, who was jailed for six months in 2002 for revealing official secrets, said it would be possible with the help of other parties. "If Reg can beat Blair, then they'll be dancing in the streets of Baghdad and Kabul, as well as large parts of Britain," he said.